[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1236172646.5330.7450.camel@laptop>
Date: Wed, 04 Mar 2009 14:17:26 +0100
From: Peter Zijlstra <peterz@...radead.org>
To: Ingo Molnar <mingo@...e.hu>
Cc: lkml <linux-kernel@...r.kernel.org>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] lockdep: fix incorrect state name
Subject: lockdep: fix incorrect state name
From: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Date: Wed Mar 04 13:51:13 CET 2009
In the recent mark_lock_irq() rework a bug snuck in that would report the
state of write locks causing irq inversion under a read lock as a read
lock.
Fix this by masking the read bit of the state when validating write
dependencies.
Reported-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
---
kernel/lockdep.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
Index: linux-2.6/kernel/lockdep.c
===================================================================
--- linux-2.6.orig/kernel/lockdep.c
+++ linux-2.6/kernel/lockdep.c
@@ -2016,7 +2016,8 @@ typedef int (*check_usage_f)(struct task
enum lock_usage_bit bit, const char *name);
static int
-mark_lock_irq(struct task_struct *curr, struct held_lock *this, int new_bit)
+mark_lock_irq(struct task_struct *curr, struct held_lock *this,
+ enum lock_usage_bit new_bit)
{
int excl_bit = exclusive_bit(new_bit);
int read = new_bit & 1;
@@ -2044,7 +2045,7 @@ mark_lock_irq(struct task_struct *curr,
* states.
*/
if ((!read || !dir || STRICT_READ_CHECKS) &&
- !usage(curr, this, excl_bit, state_name(new_bit)))
+ !usage(curr, this, excl_bit, state_name(new_bit & ~1)))
return 0;
/*
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists